<?php
/**
 * Created by PhpStorm.
 * User: dell1
 * Date: 2016/9/28
 * Time: 19:44
 */
header('Content-type:text/html;charset=utf-8');
function getFileExt($path){
    $ext=substr($path,strrpos($path,'.')+1);
    return $ext;
}
$path='C:\images\apple.jpg';
$ext=getFileExt($path);
echo "<p>文件路径: $path</p>";
echo "<p>文件后缀:$ext</p>";
?>